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  • 1.
    Abrahamsson, Erika
    Karlstad University, Faculty of Health, Science and Technology (starting 2013).
    Gröna tak - potentialen för dagvattenreglering i Karlstad: Simuleringar i Mike Urban2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    As urban areas become more populated and denser, stormwater management becomes an important matter. Since natural areas are becoming exploited and green areas in cities are removed the stormwater flow increases due to the conversion of impermeable surfaces into hard surface areas. The increase in stormwater flow can cause flooding if the pipeline system is insufficient.

    Change in climate caused by anthropogenic emissions will expose our communities to difficult challenges. Urban flooding from sewers is one of them, and may become more frequent in parts of the world where precipitation is predicted to increase in the future. In order to develop our cities in a sustainable manner and create resilience, the urban drainage system has to be a part of this development. Many of the techniques related to sustainable urban drainage systems, like storage reservoirs and open channels, require access to land space. However, about 40-50 % of the impermeable surfaces in cities consist of roof. Consequently, an interesting alternative to decrease stormwater flow is green roof due to its ability to reduce and attenuate the flow.

    The aim of this thesis is to demonstrate the benefits of green roof’s stormwater management through simulations in Mike Urban. The simulations are made over two neighborhoods in Karlstad with future climate changes. The simulations indicated that green roof in these neighborhoods show good potential to lower the risk of flooding and the numbers of flooded wells by a 10- and 2-year rain is decreased by 42 and 58 %.

  • 2.
    Adolfsson, Karin
    et al.
    Karlstad University, Faculty of Economic Sciences, Communication and IT.
    Albinsson, Stina
    Karlstad University, Faculty of Economic Sciences, Communication and IT.
    Friår - av vilken anledning?: Kopplingar mellan anledningar till friår och livsformerna2007Independent thesis Basic level (degree of Bachelor), 10 points / 15 hpStudent thesis
    Abstract [sv]

    Undersökningens syfte är att se vilka anledningar individen har till att välja friår och hur det kopplas samman med livsformerna de lever. Syftet har också varit att se individens upplevelse av friåret och vad de använt friåret till. Undersökningen bygger på kvalitativa intervjuer med sex friårslediga. Intervjuerna har handlat om individens upplevelse av friåret och tiden före det.

    Friår är en arbetsmarknadspolitisk åtgärd med målsättning att ge arbetstagare en längre ledighet från sitt arbete. Arbetslösa får samtidigt en chans att komma in på arbetsmarknaden. Friåret innebär att vara ledig från sitt arbete i tre till tolv månader för att kunna göra något annat utanför arbetsplatsen. För att kunna undersöka av vilka anledningar individen har friår och hur det kopplas med de olika sociala strukturer som villkorar människors vardag. Vi har studerat om livsformsanalysen kan användas till att beskriva, förklara och förstå skillnaderna i människors vardag. Livsformerna är sociala strukturer som villkorar människors vardag. De olika livsformsbegreppen som vi har använt oss av är arbetarlivsformen – husmorslivsformen, karriärenslivsform – representationshustrunslivsform och självständighetens livsform – medhjälperskans livsform. Det är dock vanligt att leva en blandning mellan två eller flera livsformer, det kallas en blandform.

    Vi har kommit fram till att livsformerna till viss del kan kopplas samman med hur intervjupersonerna lever under sitt friår och av vilken anledning de har friår. Det visar sig i att de som använder friåret till att starta ett företag lever till stor del självständighetens livsform. Att använda friåret till utbildning kan kopplas samman med karriärens livsformer. Vidare kan vi se att karriärenslivsform kan kopplas samman med att pressen på arbetet är stor och då är rekreation under friåret vanligt. Många kvinnor lever blandformer och det gör att de har svårt att kombinera de olika arbets- och kärleksformerna. De använder friåret till att ta hand om sin familj och sig själva.

  • 3.
    Afverberg, Marcus
    Karlstad University.
    Optimering vid byte av fyllningsplatta2018Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [sv]

    Denna rapport är en del av ett examensarbete på högskoleprogrammet i maskinteknik vid

    Karlstads Universitet med programkod MSGC17. Arbetet omfattar 22.5 högskolepoäng.

    Arbetet har utförts på Swegon Operations AB i Arvika.

    På fabriken i Arvika tillverkas ljuddämpare för ventilationssystem. I tillverkningscellen där

    dessa ljuddämpare tillverkas sker ett moment där en platta ska bytas mot en annan platta av en

    robot, detta moment fungerar inte optimalt och orsakar stora störningar i produktionen. Dessa

    plattor kallas fyllningsplattor. Varje modell av ljuddämparna har en egen fyllningsplatta. Vid

    tillverkning måste dessa plattor alltså bytas vid byte av storlek av ljuddämpare. Målet med

    projektet är att hitta en lösning på problemet.

    För att nå målet med projektet utfördes arbetet enligt produktutvecklingsprocessen. Utifrån

    förundersökningen som bestod av att samla in data om hur situationen såg ut idag och vad

    som felade skapades en kravspecifikation för den nya lösningen. Koncept skapades i

    idégenereringsprocessen som sedan sållades för att ta fram den bästa lösningen. En

    layoutkonstruktion skapades av konceptet.

    Projektet resulterade i en lösning där alla fyllningsplattor ersattes med en fixerad platta som

    passar alla storlekar av ljuddämparna. Detta genom en fyllningsplatta med slitsade hål som

    fyllningsrören kan förflytta sig i med hjälp av motordrift. Detta medför att roboten helt enkelt

    kan tas bort.

  • 4.
    Ahl, Daniel
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Analysis of how different mesh functions influence the result in CFD-simulation of a marine propeller:  2013Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
  • 5.
    Ahl, Elin
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013).
    Nordberg, Nina
    Karlstad University, Faculty of Health, Science and Technology (starting 2013).
    Planning a digital transformation for a company with a process layout: A study conducted at voestalpine Precision Strip AB2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Digitalization is an upcoming trend that divides the manufacturing industry of today. As an increasing number of companies chose to implement digitalization as a business strategy, some companies still struggle with implementing digitalization into their businesses.

    Previous research has developed digital transformation models, but has been admitted as too generic. This thesis used the most comprehensive transformation model as base and aimed to make it practically implementable for a manufacturing company with a process layout. To enable this, a case study was conducted on a steel-processing company with this layout design. This thesis had an inductive approach, where primary data were collected from one selected company through a pilot study and semi structured interviews, and secondary data were collected through a literature review.

    During the study, it was discovered that a company can benefit from using a customized guidance of how to implement digitalization, to optimally use digital opportunities. This thesis contributed with additional steps and extensions of the previous transformation model. The contribution consisted of the involvement of competency, creation of definition, identified digitalization trends relating to a SWOT analysis, additional phenomenon to take into consideration when analyzing future scenarios, additional questions to consider when analyzing impacted areas, creation of a digital business strategy, a comparison of impacted areas with previous projects, additional identified actions to fill the gap between current state and goals, and five identified criteria’s on how to prioritize these actions. This study extends current research with details and depth regarding a digital transformation model, and hence make it more practical. For future research, a case study testing the potential of the transformation model on a similar company should be conducted, and thereby improve the model further.

  • 6.
    Ahrnens, Alexander
    Karlstad University, Faculty of Health, Science and Technology (starting 2013).
    Lägesställare med I/P-omvandlare som alternativ2016Independent thesis Basic level (degree of Bachelor), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    This report covers a project instigated by Lennart Proper, Aspervall Instrument AB. The report deals with the development of Aspervalls pneumatic actuator, ASPEdonet and it is a part of the course degree project of Bachelor of Science in Mechanical Engineering, MSGC17. The course covers 22.5 ECTS credits and it was accomplished during the spring term of 2016 at the faculty of health, natureand engineering, Karlstad University. Aspervall is a company located in Säffle that specialize in precision engineering, contract manufacturing and development of own products like ASPEdonet. ASPEdonet is a pneumatic actuator constructed of a pneumatic double-acting cylinder and a positioner. The pneumatic cylinder is used to convert air pressure into mechanical work through the moment of a piston with piston rod in a cylinder tube. The positioner is used to regulate the pressure to different sides of the piston with the use of a control signal. The thesis objective was to further develop the pneumatic positioner by converting it to electropneumatic, which means that the previous pneumatic control signal was replaced with a electronic analog control signal. This was accomplished through installing proportional technology into the positioner in the form of an I/P-transducer. I/P-transducer is also preferred to as E/P-transudcer or proportionalvalve, is a pressure regulator that is used to regulate air pressure proportional to an electronic signal. The problem definition of the project was how the positioner could be complemented with a I/P-transducer without compromising the basic function or the design of the positioner. The project followed the different stages of the product development process, pre-study, product specification, idea generation, concept selection and structure with detail design. The project resulted in a documentation that can serve as basis for product manufacturing and further development. The solution that was generated has the same basic construction and design as the previous model. Norgren VP12 was selected as I/P-transducer since it is compact enough to be integrated in the positioner. Standard components from Norgren and Nelco served as fittings and cable gland. A new more compact valve was designed as a part of the construction, the valve is manufactured from a single unit.

  • 7.
    Aiki, Toyohiko
    et al.
    Gifu University, Japan.
    Anthonissen, Martijn
    Eindhoven University Technology, Netherlands.
    Muntean, Adrian
    Eindhoven University Technology, Netherlands.
    On a one-dimensional shape-memory alloy model in its fast-temperature- activation limit2012In: Discrete and Continuous Dynamical Systems. Series S, ISSN 1937-1632, E-ISSN 1937-1179, Vol. 5, no 1, p. 15-28Article in journal (Refereed)
  • 8.
    Alexandersson, Jenny
    Karlstad University, Faculty of Health, Science and Technology (starting 2013).
    Förändring av layout och produktionsflöde: Med fokus på förbättringar och struktur i produktionen2018Independent thesis Basic level (degree of Bachelor), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    This project has been implemented as a degree of Bachelor of Science in Innovation and Design at the Faculty of Health, Science and Technology at the University of Karlstad. The project started in November 2017 and continued to May 2018.

    The most of the work has been performed on the company KD: Solskydd AB in Degerfors. The main task of this project was to develop a new flow-oriented factory layout, to one of the departments in the company. The work included many observations and interviews, it was a big part of the specification and preliminary study. The analysis part of the project was to investigate the possibilities to a better flow in the production and opportunities for improvement in the factory. The methods that were used in this project were establish in Lean.

    From the product development process strategy have a project can be formed and performed. The process has been adapted to this project.

    Ten separate ideas of layouts were made. Each idea fulfilled the specification different. A group of selected co-workers from the compony and some of the persons in the board of the company, got a presentation of the ten ideas. The group discussed the separate ideas from the information they have of the ideas, from that they select one of the layout ideas. To be the one!

    A simulation of the new layout was performed in Karlstad Lean Factory. Nine employees from the company participated in the simulation. The simulation helped the co-workers to see improvements in the production flow.

    In the end of the project investigated the possibilities to more improvement areas in the company, with help from Lean.

  • 9.
    Alfredsson, Svante
    Karlstad University, Faculty of Health, Science and Technology (starting 2013).
    Konceptutveckling av transportlösning för kaffeutrustning till event2016Independent thesis Basic level (university diploma), 180 HE creditsStudent thesis
    Abstract [en]

    This thesis is done during the spring semester 2016 for the Bachelor of Science in Innovation and Design programme at Karlstad University. The mission of the thesis was provided by the company 3TEMP AB in Arvika.

    In order to serve large quantities of coffee at big events, festivals and fairs a powerful coffee machine is required. Due to its size the machine is difficult handle during transport. This project is about finding a solution that makes the transport of the coffee machine and its related equipment safer and easier to handle during transportation between events.

    The goal of the project was to find a possible solution that makes the transportation of the equipment more efficient and ergonomic. In order to find as many ideas as possible the design process has been used. This includes a research followed by an ideation, concept development and concept evaluation. The project ended with one concept presented in the form of a layout design in CAD together with assembly drawings, sketches and a model.

    In this project interviews and observations has been done together with the people who transport coffee equipment on a daily basis. The results of the observations were later compared with the recommended lifting weight for manual lifting tasks using NOISH lifting equation. In the event business different types of vehicles are used to transport equipment at the event areas. Everything from ATVs and snowmobiles to tractors and caterpillar vehicles are used. In the project there has been a search for a common denominator between those vehicles.

    During the project benchmarking of similar products has also been done to find inspiration for new ideas. To further evaluate the concepts an examination of laws and regulations for transportation of equipment in traffic and off-road has been done.

    The equipment also has to withstand long distance transport by rail, road, sea and air. To meet these requirements interviews were made with the company MariTerm AB who works with educating in cargo securing of goods for worldwide shipment.

  • 10.
    Almström, Daniel
    Karlstad University.
    Organizational Misbehaviour: Om olika yrkeskategorier – En jämförande studie2007Independent thesis Basic level (degree of Bachelor), 10 points / 15 hpStudent thesis
    Abstract [sv]

    I denna studie kommer jag att jämföra kollektivanställda och tjänstemän på en större processindustri i Värmland. Syftet med att jämföra de olika grupperna är att se om det skiljer sig mellan handlingar som kan tolkas som organizational misbehaviour.

    Denna studie är utav en kvantitativ karaktär där graden av organizational misbehaviour har undersökts mellan de två yrkesgrupperna med hjälp av enkät. Urvalet omfattar totalt 300 stycken anställda, respondenterna var jämnt fördelade mellan de olika yrkesgrupperna för att göra en så rättvis undersökning som möjligt.

    Jag har valt att mäta Organizational misbehaviour i följande variabler (1) om de anställda använder Internet till privata syften (2) ringer privata samtal på arbetsgivarens telefon (3) gör privata ärenden på betald arbetstid (4) om det förekommer skämt om sina kollegor och chefer (5) stöld på arbetsplatsen.

    Jag har kommit fram till att det finns en skillnad mellan de olika yrkesgrupperna. Denna skillnad beror främst på vilka möjligheter de anställda har genom sin anställning. Det har visat sig att om de anställda har tillgång till Internet och en fast telefon som betalas av bruket så ökar frekvensen bland de anställda att begå handlingar som kan kopplas till organizational misbehaviour bland de anställda. I denna undersökning så kan även se en skillnad mellan män och kvinnor i handlingar som kan tolkas som organizational misbehaviour.

    Jag har även kommit fram till att det finns klara skillnader mellan de anställda beroende på hur länge man har varit anställd på bruket. Studiens resultat visar bland annat att en bidragande anledning till att anställda ägnar sig åt organizational misbehaviour är att de missnöjda med sitt yrke. I denna studie så kommer jag att arbeta efter fyra frågeställningar dessa är;

    -Förekommer det organizational misbehaviour bland de anställda på bruket?

    -Finns det någon skillnad i organizational misbehaviour bland tjänstemän och

    kollektivanställda bruksarbetare?

    -Finns det skillnader i organizational misbehaviour beroende på hur länge man har varit anställd på bruket?

    -Finns det någon skillnad i organizational misbehaviour mellan de olika könen?

  • 11.
    Alvarsson, Kristoffer
    Karlstad University, Faculty of Health, Science and Technology (starting 2013).
    Ombyggnation av en svetscell: Utformning av inmatningssystemet2015Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    This report deals with a project that´s been initiated on the behalf of Morgan Sahlin at Wermland Mechanics AB in Töcksfors and is about to look over and develop a input system for a welding cell. The project is done in the course Degree of Bachelor of Science in Innovation and Design Engineering, MSGC12 at Karlstad University and comprises 22,5 credits.

    Today the company has received a shelf in the production where one of the steps is to apply a reinforcement by welding. At their disposal, they have a welding cell that today is just standing still, taking up space and costs money. The welding cell has previously been semi-automatic but the company now wish to rebuild it so it instead becomes fully automatic. The goal is to develop a concept that suits the company's operations and that at the end of the project gaze upon a functioning fully automatic welding cell.

    The project follows a project model based on the product development process with the phases pilot study, concept generation, concept selection, concept description, layout and detail design. Each phase is supplemented with specially selected design tools. During the process analyzes, observations, interviews and site visits has also been carried out.

    After the pilot study that was based on observations, analysis and gathering of information, a specification took form where the requirements and requests, of what the final product is expected to achieve, were listed. The specification resulted in the project´s first problem: "How should a feed mechanism to an automated welding cell be designed that allow room for shelves and reinforcements, with focus on the user-friendliness?". This problem was the foundation of the upcoming concept generation and the specification became the basis of the choice of concept.

    The process resulted in two concepts that were presented to the client and which corresponded to the established definition of the problem. Both concepts are based on exploiting how the details arrives and means that they are entered directly into the welding cell on the pallets. The concepts differ in how the shelves are stacked on the pallets, one comprises a solution where the shelves are laying down while in the other one they are standing up. The solution suits the company well and can be adapted to most of the operations in their production.

  • 12.
    Anders, Ylén
    Karlstad University, Faculty of Health, Science and Technology (starting 2013).
    Införande SPS Arvika Smide AB: SPS och ISO/TS 169492014Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    The report is a master thesis carried out in the final part of the Bachelor of Science education in Mechanical Engineering. The work is carried out by Anders Dedorsson Ylén, a student at the Faculty of Health, technology and natural science at the University of Karlstad.

    The work has been performed at Arvika Smide AB, whose mission was to introduce SPS at the pressgroup 5, and examine how well the company is working with ISO/TS 16949.

    The report contains a theoretical part about SPS and ISO standard ISO/TS 16949.

    It also describes how SPS can be used as a method for measuring machine condition and maintenance needs, and how the test's are carried out.

    It describes what has happened in the renovation of the forging press, and the results of measurements made after the renovation work was done.

    An appropriate method is presented to be able to see where the company is in its work with ISO/TS 16949 and suggestions for improved work with ISO/TS is suggested.

    The report shows that the SPS can be used as a guideline in condition-based maintenance of a forging press and how the company can improve its work with ISO/TS 16949.

  • 13.
    Andersson, Andreas
    et al.
    Karlstad University, Faculty of Technology and Science.
    Andersson, Anders
    Karlstad University, Faculty of Technology and Science.
    Kostnadseffektivisering av bärcylinder2007Independent thesis Basic level (professional degree), 15 points / 22,5 hpStudent thesis
    Abstract [en]

    The report intends a thesis work within the machine engineer program at Karlstad University, the employee is Metso Paper Karlstad AB

    Metso Paper produces tissue machines for the paper industry and also performs service and development of these products. Tissue is soft paper which includes hygiene paper and table napkins. Focus in the task is to reduce the cost of the reel drum, which is a detailed component in a tissue machine. The reel drum is a drum which is assembled in the end on the paper machine, in the area where the paper is rolled up on spools. The analyzed items have the dimensions; diameter 900mm with the length 2825 mm and diameter1100 mm with the length 5550mm.

    Initially, the reel drum’s main functions were analyzed, which can be summarized:

    • That with vacuum transport the point (narrow paper chute) from the point swindle groove to the surface between the reel drum and the reel spool

    • To support paper during winding on the reel spool

    • To create a pressure against the reel spool so that a driven torque arises. The torque is required because the reel spool has no own power supply.

    The task was divided in two parts for a simpler procedure,” new structure” and ”improvement and efficiency improvement of existing structure”

    New structure treats calculations concerning the thickness of the shell and choices of alternative materials. Improvement and efficiency concerns how the current structure can be simplified and the production process improved. The result demonstrates that today's structure is unnecessary thick, the shell thickness l can be reduced with maintained function properties. To produce the shell in steel instead of cast iron gives lower purchase cost of materials for reel drums in diameter 900mm, buying to shells at the time almost reduces the material cost with 50%

    In order to make the existing structure and the production process more effective must certain parts of the casting be carried out with higher precision, criteria such as: thickness, roundness and presence of rest products should be taken into consideration. Higher casting precision makes the following machine work easier.

    Finally there exists a big potential to reduce the cost of the reel drum. Important criteria’s that is to be considered are: dimensions, materials and more effective processing.

  • 14.
    Andersson, Björn
    et al.
    Karlstad University, Faculty of Technology and Science.
    Fransson, Andreas
    Karlstad University, Faculty of Technology and Science.
    Användning av CAD-data vid NC-programmering2007Independent thesis Basic level (professional degree), 15 points / 22,5 hpStudent thesis
    Abstract [en]

    The degree project is performed at Metso Kamfab. The production is aimed on machines everything from handling of fiber to paper pulp. Metso Fiber and Kamfab are using Pro/Engineer for design and blueprint production. The processing department types the NC-programs in notepad on the basis of the blueprints, the CAD-dates that already is there are not used. The aim with the work is to study if Kamfab can use CAM-system for processing and production of programs for their NC-machines. The objective in this project is to make NC-programs that functions in three special machines.

    CAD/CAM forms the link between design and production. In a CAD/CAM-system the geometry is created in CAD and can be used directly in CAM for processing. In CAM CL-data is created and after that translated with a postprocessor to NC-code. The postprocessor is used also as a watch over function.

    Three machines were chosen as experiment items for introducing of CAD/CAM. These are a 7-axis mill, a combined mill/turn and a 3-axis mill. The 7-axis mill and the mill/turn were chosen because they are the most advanced machines. The 3-axis mill was chosen because there was available time in it. Products that were tested were trough, pillar, housing and a part for a toolchanger.

    When processing the trough ”Surface-Mill” was chosen and a lead-angle was set in the parameters. It was most drilling and a little face milling on both the pillar and the housing.

    In order to test programs a postprocessor was borrowed that translated CL-data to Heidenhain code. During the test run errors were detected in the programs. This depends on that the postprocessor not where customized for the machine. A postprocessor developed by ourselves was also tested, this one didn’t work because the machine's NC-system couldn’t read ISO standard code.

    A study visit was done at Structo in Kristinehamn where EdgeCAM is used for NC-processing. It works well and it allows quicker and safer programming.

    Pro/Engineer is powerful and has a lot of possible adjustments. This makes it complex and takes time to learn. To use Pro/Engineer´s CAM-part it is necessary to have basic knowledge about the CAD-part. Depending on this many companies uses for example EdgeCAM that almost is a pure CAM-system.

    The processing of the three components functioned well in Pro/Engineer, we could process the components after demands. The problem was to get working programs. An advantage with using CAM is that you can simulate toolpaths. Through this you can see if the tool collides and it also makes it possible to optimize toolpaths. Today, it is a lot of waiting time in the milling machine FPT34 because programs are not completed. This waiting time would be reduced or even eliminated with the aid of CAM.

  • 15.
    Andersson, Camilla
    et al.
    Karlstad University, Faculty of Economic Sciences, Communication and IT.
    Johansson, Maria
    Karlstad University, Faculty of Economic Sciences, Communication and IT.
    Att vara eller inte vara: styrs uttaget av föräldraledighet av föreställningar eller faktiska förhållanden?2006Independent thesis Basic level (degree of Bachelor), 10 points / 15 hpStudent thesis
    Abstract [en]

    The purpose of this survey is to investigate how well parents ideas and conceptions concerning parental leave, matches factual circumstances, or if there is a difference? More specifically it has been investigated if it is the common conceptions concerning the obstacles for the male parental leave which is in control, or if it is the actual circumstances which control the parental leave? The survey is based on a quantitative empiric where the collection of data has been done through a selection of availability with a questionnaire as the measuring instrument.

    In order to find the answer to the question at hand, theory in the field of parental leave and gender has been studied. The theory section contains a presentation of the parental leave discourse with its four obstacles; economy, workplace, the woman and the gender roles. The section is the base of our understanding and has also been the framework from which the questions for the survey have been constructed.

    The results from the empirical survey have been analyzed together with relevant literature to give an answer to the question at hand. From this it can be read that the distribution of the days of the parental leave is highly affected by the conceptions and ideas males face concerning parental leave. The results also clearly show that the obstacles partially are not rooted in reality. In the survey it also surfaced that those responding had insufficient knowledge concerning the parental insurance which we believe has aided the conceptions and ideas to the influence and degree they have had. The authors hence believe that the information to the parents should improve and that researches in the field should find strategies in order to better inform the public of their knowledge.

    Keywords: Parental insurance, parental leave, gender system, discourse and obstacle

  • 16.
    Andersson, Christian
    Karlstad University, Division for Engineering Sciences, Physics and Mathematics.
    Förbättring av utnyttjandegrad hos stansmaskin2008Independent thesis Basic level (degree of Bachelor), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [sv]

    Bakgrunden till examensarbetet är att det finns ett behov av att höja utnyttjandegraden i stans- och lasermaskiner hos Lars Höglund AB. Anledningen till att utnyttjandegraden behöver höjas är att företaget vill bli mera lönsamt och mera konkurrenskraftigt.

    Uppgiften har varit att mäta utnyttjandegraden, göra en probleminventering och ta fram förslag på åtgärder som kan lösa de problem som kom fram i probleminventeringen.

    Vid probleminventeringen visade det sig att det går att höja utnyttjandegraden genom att bl.a. göra en ställtidsreducering, skapa ordning och reda, samt att förebygga flaskhalsar.

    5S är en metod som har använts för att ta fram förbättringsåtgärderna. Genom att följa denna metod, samt att göra några nya investeringar i företaget, ser det ut som att målet i detta arbete ska kunna uppnås.

  • 17.
    Andersson, David
    Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Förstudie för förbättrad problemlösning och förbättringsarbetet hos Mastec Stålvall2013Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
  • 18. Andersson, Erik
    Hydrostatisk drivlina: För tunga lastfordon2012Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
  • 19.
    Andersson, Erika
    Karlstad University, Faculty of Arts and Social Sciences (starting 2013), Department of Educational Studies.
    De fem enkla maskinernas integrerande i den fria leken inom förskolans arena: En studie baserad på barns undersökande av enkel teknik i den fria leken.2017Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The purpose of the study is to demonstrate how children apply simple technology in preschool through “The Big Five”. Observations and "Interview on the move" are the method choices that answer the purpose and questions of the study. Observations and interviews have been conducted in the preschool outdoor environment during a morning and are based on the children's free play where the aim is to start from the children's perspective and reflections. The situations that have been chosen for the study are based on the children's curiosity and demonstrated interests. The result of the study shows that two of “The Big Five” are applied by the children in the preschool outdoor environment and free play. This is demonstrated by their use of the leaning plane and the wheel from “The Big Five”. It shows by their use of tools such as exploration, part of the game and through concepts. This is done through a sociocultural perspective where different factors influence children's learning.

  • 20.
    Andersson, Gustav
    -.
    Handling-Force Software: Calculation software for tailgate and bonnet in concept stages2019Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    Abstract

    This report focuses on the creation of a software to calculate handling forces of bonnet and tailgate. The handling force is the force required by a user to open or close a tailgate. It is a bachelor thesis conducted for Karlstad’s university. The work is conducted at CEVT in Gothenburg, the software will be used to improve workflow in early design phases.

    The resulting software from this project is easy to use and shows good resemblance to the reference values, which is old calculations done by a manufacturer. Comparing to manufacturer calculation the software shows only small deviations in results. The software is deemed to be an asset in the development work at CEVT.

    The software is also easy to use and have been tested by employees, whom could operate the software easily without instructions. It is based on regular equilibrium equations and the software structure is logical and easy to follow, to make it simple to maintain and develop the software if the need would arise.

    The finished software calculates single pivot hinges and four bar mechanism-based hinges equipped with gas springs. It also has the possibility to work with tailgate and bonnet simultaneously to keep one project in one file.

    The work has focused on, creating the software, user interfaces and kinematics/kinetics of different types of hinges, with support from both literature and reports. This led to a software built in Microsoft Excel, which was chosen due to its standard features for graphical display of data. Building the software in Excel also makes it accessible to all employees who wishes to use it.

    The conclusion is that the software could in extension lead to higher quality on finished products by allowing more tested configurations and continuous changes during the design process.

  • 21.
    Andersson, Jim
    Karlstad University, Faculty of Health, Science and Technology (starting 2013).
    Manufacturing of Welded Rings: Evaluation of Post-Weld Operations2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Pipe and ring blanks can be produced in several different ways. Today's focus on environmental effects motivates companies to develop processes that are as efficient as possible in their production. Ringsvets AB is a company that produces pipe and ring blanks from a flat stock by rolling and welding the piece to make it stay in its desired form. The direct benefit of the method is the minimizing of material loss, and it has thereby both environmental and economical advantages. The downside of the method is that the processes involved changes the mechanical behavior of the ring, locally around the weld zone. The focus of this master thesis is the processes and how they affect the material, both microstructure and behavior. The processes involved are; rolling, welding, shaping, brushing, forging, heat treatment, and calibration.

    The purpose of this work was to elevate the knowledge and understanding of the processes at Ringsvets. The goals were to give a theoretical description of them along with practical test results and explanations of how and why they function in reality.

    A literature study has been conducted which provided a theoretical basis on how the material reacts on certain processes. Practical examination of samples from current production has been done to get evidence of how well the processes are used, and how well they function, in today's production. Lastly, the main focus of the thesis, an evaluation has been made; do theory and practice correlate, and should anything be changed to correlate better?

    The results showed that the first operations do not alter the material behavior to an unacceptable extent. Forging, on the other hand, gives the material a very high hardness in the weld zone, and that needs to be corrected. The following heat treatment should compensate for that in a perfect world, but does not in reality. The finished ring shows good properties in general but with places where the heat treatment has failed to correct the uneven behavior induced by earlier operations.

    The heat treatment requires some adjustments before it functions as intended. Some grainshas not been recrystallized which makes them very hard and non-ductile. Future tests using a higher temperature or a longer heat treatment time would reveal the best way to adjust the heat treatment to obtain the desired properties. Other changes in the processes could also be benecial. Interesting things to try and change would, for example, be the degree of deformation in the forging, which affects the recrystallization temperature.

    Notes should be taken that this examination is done on just one sample of just one size. Analyses of different samples of different sizes should be done to ensure of the accuracy of the examination.

  • 22.
    Andersson, Johannes
    Karlstad University, Faculty of Health, Science and Technology (starting 2013).
    Förbättring av Camcoil: Integrering av stöd samt bandnyp2013Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    Abstract

    The assignment were assigned by Camatec Industriteknik AB. Camatec is a Karlstadlocated consulting company, they make everything from pilot studies to complete projects in mechanical design and calculation. They even have their own patented product, Camcoil. It is a winder for steel strips and is used for example with hardening of the steel strip. The assignment has been to solve the problems encountered by some customers within this product. The product which is relatively simple consists of a mantle which can vary in diameter by means of hydraulic cylinders The problem was that it had concurred indentations on the striped steel next to the Camcoil. This destroys the further handling of the coil. The goal has been to develop three kinds of solutions that take into account different customer requirements. These solutions have been divided into price ranges, thus low-cost, mid-cost, and high-cost. The high-cost solution has been a combination of the mid-cost-solution and a bandgrip. One wish was to simplify the existing bandgrip.

    The functional requirements those are set depending on the customer:

    • Must be able to prevent sagging, then some form of support should be available to the band at reeling.

    • Not allowed to weld in the mantle beneath the welded ears.

    • Must be able to take a band-pull at max 1 ton.

    • The space at the clearance on the reel should be free at the use of lifting hook (midcost, high-cost)

    • Steel strip with thickness 0.2-1 mm is to be pinched to the reel (High-cost).

    • A stop for the band at pinching must exist (high-cost).

    The non-functional requirements that have applied for all price ranges:

    • Develop the simplest solution as possible.

    • Standard components recommend being used to reduce costs.

    • The solution should be user friendly and easy to maintain.

    The major problem has been the lack of space in the reel with the requirements of midcost solution. Due to a lifting hook to be used it has been very difficult to come up with a mechanism that would work as a support. A comprehensive concept generation has been done with a number of different concepts for each price ranges solution. The concepts have been evaluated and compared and with the help of elimination- and decision matrix has a concept selection for each price range been developed. The result for the low-cost solution is a rolled sheet metal that is overstrung on the outside of the mantle, this means when the mantle will collapse the rolled sheet metal will follow along. Mid-cost solution resulted in a mechanical lid uses mantle movement with the help of parallel rods wander vertically down and account the space for the lifting hook. A simplification of the bandgrip were made with boomerang stays, this gave more space and fewer parts. The combination of the mid-cost solution and the simplified bandgrip were the high-cost solution.

  • 23.
    Andersson, Kimberly
    Karlstad University, Faculty of Health, Science and Technology (starting 2013).
    Parametriska symboler för utrustningsritningar inom processindustrin2014Independent thesis Basic level (professional degree), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    On behalf of CWR Engineering AB a development project has taken place. The goal of the project was to determine whether or not it is possible to create an application which can make working process of the mechanical engineer, in the process industry, run with higher quality assurance and efficiency whilst creating equipment drawings. The development process within process industry strives towards being cross- functional. All design is based on the Piping and Instrumentation Diagram (P&ID), where the process, for example a chemical plant, described in 2D where the piping, equipment and instruments are specified to type, but not position. The equipment is then described in detail in a 2D drawing. The 2D drawing in turn is the basis for the equipment when creating it in 3D. Finally, the 3D model is placed into the factory layout in a 3D environment. The factory layout correspond to the design determined in the P&ID.

    An equipment drawing differs from a standard mechanical drawing in the sense that it has no standard for its views, such as a mechanical drawing can be designed by either a European or an American standard. The equipment drawing must however still meet the requirements of defining all components described within the P&ID, which can be done in some different ways. The format for these drawings creates possibilities for error, which the developed application is to prevent. In this project, the study was limited to tanks with its nozzles.

    The project has resulted in a layout concept for an application in the engineer's computer environment which creates a built-in error-proofing in the working process. It makes the process more efficient. The concept has been developed through analyzing the working process used today and the software the engineer uses in his work. A flow for the technical information have been identified and based on these data, the concept has been developed.

    The layout concept consists of three parts. First, a drawing file management form which creates, deletes, revises and correlate the status of all equipment drawings to the data in P&ID. All data from these diagrams are stored in a Microsoft SQL Server database. Using Microsoft Visual Studio this data can be used to create, manage and control the equipment drawings in a semi-automated way. The drawings are created in 2D CAD software SmartSketch. The SmartSketch user is currently using symbols, which are pre-drawn static components which the user can place on the drawing and then scale to preferred size. These symbols are available in various executions depending on the nozzle to be placed. The second part of the concept consists of making these symbols dynamic and driven parametrically through a dimensions database. Information about the standpipe size, dimensions standard, pressure rating and end preparation comes from the P&ID data, which then retrieves information about parametric dimensions in a database. The symbol automatically receives correct dimensions and can be placed on the tank. The amount of symbols can therefore be reduced since the symbol's graphic changes parametrically. If any variable of the nozzle is be changed, the symbol will automatically be updated. The user can also manually change variables such as size and pressure class, even before the changes take place in the P&ID, as a part of cross- functionality. The third main functionality of the concept is the examination of the drawing data pertaining to the positioning and view conformity of the nozzles. The examination result is to be reported in a PDF file and in a dialog window.

  • 24.
    Andersson, Malin
    et al.
    Karlstad University, Division for Business and Economics.
    Hedlund, Emma
    Karlstad University, Division for Business and Economics.
    Ledarskap: En jämförande studie mellan personalchefer och andra chefers ledarskap2006Independent thesis Basic level (degree of Bachelor), 10 points / 15 hpStudent thesis
    Abstract [sv]

    Sammanfattning

    Denna C-uppsats i arbetsvetenskap är en kvalitativ studie och baserad på teorier om ledarskap. Syftet med uppsatsen är att undersöka likheter och olikheter mellan personalchefer och andra typer av chefers ledarskap.

    Inledningsvis presenteras en historisk bakgrund av ledarskapets förändring. Sedan följer grundläggande ledarskapsteorier samt teorier om kommunikation, makt, motivation och genusperspektiv. Dessa teorier är en viktig grund för analys- och resultatavsnittet i uppsatsen. Utifrån dessa teorier utformas en intervjuguide. Datainsamlingen sker genom intervjuer. Totalt genomförs sammanlagt sex intervjuer. Respondenterna är en områdeschef, en affärsområdeschef, en kontorschef samt tre personalchefer. Intervjuerna transkriberas och vi undersöker likheter och olikheter gällande ledarskap mellan personalchefer och övriga chefer. Vi får fram följande teman: synen på ledarskap, att vara ledare, utveckling av ledarskapet, ledarstilar, kommunikation, motivation, makt och ledarskap ur ett genusperspektiv. En sammanfattande diskussion av analys och resultat görs. Uppsatsens slutsats är att personalcheferna, i större utsträckning än de övriga cheferna, inte bara automatiskt bedriver ett chefskap utan också ett ledarskap.

    Nyckelord: ledarskap, likheter, olikheter, kommunikation, motivation,

  • 25.
    Andersson, Martin
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences.
    Torkning integrerat med kraftvärmeverk: Påverkan av energibalanser i torksystem vid integrering till kraftvärmeverk2016Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    I Sveg finns ett pneumatiskt torksystem. Systemet har sedan 1989 torkat torv till briketter men har på senare tid torkat både trä och torv för produktion av bränsle i form av pellets och briketter. Idag består anläggningen av två symmetriska torklinjer. I torklinjerna används en värmepumpkrets för återvinning av råvaruånga. I värmepumpkretsen används en kompressor driven av inköpt elenergi. Planerna är att integrera en av linjernas nuvarande torkprocess till ett kraftvärmeverk genom installation av ångpanna med bränslet torv och således producera el istället för att köpa el. Integrationen till kraftvärmeverket ger torklinjens värmepumpkrets ett nytt utseende. Kompressorn tas bort i utvald torklinje och ersätts av två lågtrycksturbiner. Det nya utseendet av värmepumpkretsen kommer innebära ett samspel mellan torkning och kraftvärmeverk. I värmepumpkretsen används olika ångflöden beroende av vilket råvarumaterial som torkas. Därför beräknades och användes olika ångflöden beroende av olika fukthalter och inmatningar i torksystemet för att se hur el- och fjärrvärmeproduktionen i kraftvärmeverket påverkades. Samtidigt jämfördes nuvarande torksystem med torksystem integrerat med kraftvärmeverk ur ett energiperspektiv genom förändring av el, fjärrvärmeproduktion och biobränsle.

    Fjärrvärmeproduktionen i kraftvärmeverket ökade vid ångflödena 31,0 ton/h och 24,0 ton/h ”till kompressor” men på grund av större beräkningsosäkerhet bortsågs dessa. Detta gav en varierad sammanlagd fjärrvärmeproduktion av systemen mellan 23,0-23,8 MW respektive 22,0-22,5 MW vid torkning av torv respektive trä (bortseende av torvscenario 1 vid fukthalten 65 %). En fjärrvärmeproduktion i den storleken, jämfört med Svegs fjärrvärmebehov, kan sägas vara för stort. En stor problematik blir därför vad all spillvärme ska användas till, framförallt på sommaren.

    Vid integrering till kraftvärmeverk minskade ”bränsle” medan ”fjärrvärme” och ”el” ökade. Beroende av vilket råvarumaterial som torkades gav en integrering ett större resultat för ”el” men mindre ”fjärrvärme” och ”bränsle” vid torkning av trä. Därför rekommenderas torkning av trä eftersom större resultat av ”el” minskar inköpt elenergi samt mindre ”fjärrvärme” resulterar till mindre spillvärme.

    Vid beräkningarna användes Simulink, ett verktyg för grafisk lösning av differentialekvationer, som ingår i programvaran MATLAB från Mathworks. I Simulink formerades olika ekvationer i statiska beräkningsmodeller för beräkning av energibalanserna i nuvarande torksystem och torksystem integrerat med kraftvärmeverk. Energibalanserna i nuvarande torksystem undersökte svårplacerade effektförluster samt genom olika energibalanskontroller kontrollerade och bedömde trovärdigheten i beräkningsmodellen. Resultaten för energibalanskontrollerna kallades ”beräkningsosäkerhet” vilket var en av flera parametrar som framlade bevis för ett variabelberoende, känsligt, komplext och svårtydande torksystem där övriga effektförluster var svåra att placera. Ett mer korrekt resultat av nuvarande system kan därför möjligtvis uppnås vid användande av en dynamisk istället för statisk modell samt användande enbart av mätdata istället för dimensionerande värden och således göra effektförlusterna lättare att placera.

  • 26.
    Andersson, Mattias
    Karlstad University, Division for Engineering Sciences, Physics and Mathematics.
    Kylskåpsinredning: Praktiska funktioner2008Independent thesis Basic level (professional degree), 15 points / 22,5 hpStudent thesis
  • 27.
    Andersson, Rasmus
    Karlstad University, Faculty of Health, Science and Technology (starting 2013).
    CAE Tool for Evaluation of Park Lock Mechanism in a DCT Transmission2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    A park lock mechanism is a device that is fitted to an automatic transmission on a vehicle. The mechanism lock up the transmission so that no rolling of the vehicle can be done when the vehicle is put in the park position.

    The aim of this thesis is to develop a method in order the evaluate designs on a Park Lock Mechanism (PLM) that can be found in a dual clutch transmission (DCT).

    A Computer Aided Engineering (CAE) tool to calculate the output that is required for an evaluation of a park lock mechanism design will be created. The CAE tool shall calculate static, dynamic, and snap torque on a ratchet wheel in a gradient, with or without a trailer, also the minimum and maximum coefficient of friction between the pawl and cone, pull out force, the maximum amount of rollback, torque needed from the return spring, preload force from actuator spring, and engagement speed.

    The CAE tool created uses an Excel Visual Basics for Applications (VBA) workbook for all calculations. The tool allows the user to choose different vehicles with the required specification to evaluate the values for that PLM.

    The CAE tool will save time and cost if lots of different PLM’s are going to be designed. The CAE tool has potential for future work when more calculations can be added that can be in use for the evaluation the PLM.

    The CAE tool developed by the master thesis student calculates all the required values for evaluation of a PLM design, executed in a fast, efficient, and easy to use program. 

  • 28.
    Andersson, Tim
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences.
    Computer Modeling of Thermodynamic Flows in Reactors for Activated Carbon Production2014Independent thesis Advanced level (degree of Master (Two Years)), 300 HE creditsStudent thesis
    Abstract [en]

    There's a big demand for activated carbon in Ghana, it's used for the country's mining industry as well as in a multitude of other applications. Currently all activated carbon is imported despite the fact that the country has a large supply of agricultural waste that could be used for its production. This study focuses on activated carbon production from oil palm kernel shells from the nations palm oil industry.

    Earlier research points to a set of specific conditions needed for the production. The pyrolysis process produces biochar from the biomass and the process is set to take place for 2 h at 600  °C after a initial heating of 10 °C/min. The activation process then produces the activated carbon from the biochar and is set to take place for 2 h at 850 °C with a heating rate of 11.6 °C/min.

    Two reactors are designed to meet the desired conditions. The reactors are both set up to use secondary gases from diesel burners to heat the biomass. The heating is accomplished by leading the hot gases in an enclosure around a rotating steel drum that holds the biomass. To improve the ability to control the temperature profile in the biomass two outlet pipes are set up on top of the reactor, one above the biomass inlet and one above the biomass outlet. By controlling how much gas that flows to each outlet both the heating rate and the stability of the temperature profile can be controlled. The secondary gas inlet is set up facing downwards at the transition between the heating zone (area of initial heating) and the maintaining zone (area of constant temperature).

    The two reactors are modeled the physics simulation software COMSOL Multiphysics. Reference operating parameters are established and these parameters, as well as parts of the design, are then changed to evaluate how the temperature profile in the biomass and biochar can be controlled. A goal area was set up for the profile in the biomass where it was required to maintain a temperature of between 571.5 and 628.5 °C after the initial heating to be seen as acceptable. Similarly a goal area was set for the biochar between 809 °C and 891 °C after the initial heating.

    It's found from the simulations that the initial design of the reactors work well and can be used to produce the desired temperature profiles in the biomass and biochar. Furthermore it's concluded that the initial design for the pyrolysis reactor can be improved by having the gas outlet pipe situated by the biomass inlet face downwards instead of upwards. The redesign improves the overall efficiency of the reactor by increasing the heating rate and maintained temperature.

    The evaluation of the operating parameters led to the conclusion that the secondary gas inlet temperature effects the temperature profile to a greater extent than the gas mass flow in both reactors thereby making them more energy efficient. The increase in efficiency comes with a drawback of more unstable temperature profile. If the temperature profile becomes too unstable it will include temperatures that are too high or too low to be seen as acceptable.

  • 29.
    Andersson, Victor
    Karlstad University, Faculty of Health, Science and Technology (starting 2013).
    Flödesanalys av roterande ventil i ångmotor2018Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    This report is a bachelor thesis at Karlstad University in collaboration with Invencon AB and Ranotor AB. The goal was to analyze a rotating valve leading water vapor through an inlet and five outlets. The quantifiable results that were addressed in this project are the mass flow through the outlets and the forces affecting the valve and its shaft (primarily radial forces). The tools used for this project are PTC Creo and ANSA for modelling and mesh as well as ANSYS-CFX and Matlab for computational help. The results show that the specified rotational speed of 4600 rpm doesn’t work for this model. The rotational speed was chosen because of an interest in this specific operating condition. A 3 mm radial gap between the rotating valve and the valve housing proved to cause a leakage in the form of pressure loss inside the valve. The boundary conditions that were laid out for this project are not valid for this operating condition. Since the difference in pressure is large (100 down to 1 bar) the flow is choked. A large difference in pressure also makes it important to adjust the total area of the outlets, since the pressure drop affects the density of the vapor. The forces on the rotating valve that were calculated (using ANSYS-CFX) create a foundation for choosing bearings for the valve. If the construction is modified, and/or the rotating valve will operate at a different rotational speed these forces will be subject to change.

  • 30.
    Andreasson, Frida
    et al.
    Karlstad University, Faculty of Economic Sciences, Communication and IT, Department of Working Life Science.
    Johansson, Martin
    Karlstad University, Faculty of Economic Sciences, Communication and IT, Department of Working Life Science.
    Trivsel på arbetsplatsen: En kvalitativ studie om lärares trivsel på arbetsplatsen2017Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
  • 31.
    Andrée, Fredrik
    Karlstad University, Faculty of Health, Science and Technology (starting 2013).
    Nya metoder för vibrationsmätning på vindkraftverk2015Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    This project has revolved around finding better ways of overseeing vibrations of the gearbox at a wind power station. The gearbox has been a huge problem at the stations located at Gässlingen and the sooner the warning of an incoming breakdown is at hand the more money you can save from preparations. The work has been carried out together with Askalon AB in cooperation with consults from ÅF. Askalon is a company with a department focused on overseeing vibrations and it is in collaboration with that department the work has been carried out.

     

    During this work, new positions for the sensors and new methods of gathering and analyzing data have been worked out. This was then implemented at a wind power station to be tried out on site. The measurement has been overseen online via remote control and the results have been analyzed in a program called AMS Suite: Machinery Health Manager.

     

    The new type of measurement shows that some kind of damage has been done to a specific part of the gearbox and that there is a risk it might escalate. However the measurement used today has not yet alarmed and therefor the conclusion made from this is that the project has been successful. Therefor it is time to refresh the overseeing of vibrations.

  • 32.
    Andrésen, Albin
    Karlstad University, Faculty of Health, Science and Technology (starting 2013).
    Att förutsäga temperatur, utgående fukthalt och tryckfall i en pneumatisk transporttork2014Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [sv]

    Användningen av pellets har ökat kraftigt de senaste åren och har blivit ett viktigt verktyg för att minska miljöpåverkan. I energibranschen är viktigt utreda möjligheten att effektivisera tillverkningsprocessen för att ligga i framkant av utvecklingen och göra bränslet till ett attraktivt val för konsumenterna. En stor del av pelletstillverkarnas utgifter går till att torka det råmaterial som pellets består av. Torkning och transport av material är två energikrävande processer som är nödvändiga i många industrier och kan ibland innebära stora utgifter såväl kostnadsmässigt som miljömässigt. Pneumatisk transporttorkning är ett sätt att kombinera torkning och transport av material och tekniken kan vara lämplig att använda vid pelletstillverkning. På Karlstads Universitet finns en pneumatisk transporttork vars syfte är att forska och utveckla torkning av råmaterial.I den här studien byggdes en modell för att hjälpa användaren att förutse vilket tryckfall och utgående fukthalt som kan förväntas vid torkning av sågspån. Modellen kan användas som ett hjälpmedel vid planering av försök i Karlstads Universitets pneumatiska transporttork.Modellen byggdes i beräkningsverktyget Excel. Dess resultat jämfördes med testserier genomförda i Karlstads Universitets pneumatiska transporttork. Totalt genomfördes trettiotre olika testserier då tryckfall och utgående fukthalt jämfördes. Testserierna skiljde sig ifrån varandra i fråga om massflödet luft, material och ingående lufttemperatur.Vid lägre lufttemperaturer förutsåg modellen en högre utgående fukthalt än vad som kunde uppmätas. När den ingående lufttemperaturen var 120 °C förutsågs ibland rätt, ibland högre och ibland lägre fukthalt i jämförelse med testserierna. Tryckfallet kunde med god noggrannhet förutsägas då lufthastigheten var låg. Då hastigheten var högre var differensen mellan mätdata och modellen större.Känslighetsanalysen visade att en möjlig förklaring till att modellen i vissa fall förutsåg en hög fukthalt kan vara att vissa materialegenskaper var felaktigt antagna. Störst påverkan hade antagandena angående partiklarnas densitet och antalet partiklar som flödar genom systemet per sekund. Det simulerade tryckfallet påverkades inte av ovan nämnda antaganden.Modellen har stor utvecklingspotential men vidare studier rekommenderas för att skapa en bättre förståelse för såväl den pneumatiska transporttorken som modellen. Studierna bör främst riktas mot att bestämma partikelegenskaper och att kontrollera hur väl tryckfallet överensstämmer men mätdata i hela torken. Om det genomförs finns goda möjligheter att modellen kan bli användbar för användare av Karlstads Universitets pneumatiska tork.

  • 33.
    Ankartoft, Robin
    Karlstad University, Faculty of Health, Science and Technology (starting 2013).
    Utveckling av kaffemaskin för event2016Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    This report covers a product development project conducted by Robin Ankartoft as Bachelor of Science thesis for the innovation & design engineer program at Karlstad University. 

    The assignment was provided by the company 3TEMP AB, Arvika. The company has requested a concept proposal of a coffee machine for events. The coffee machine has to be able to serve coffee fast and during long periods of time, to the visitors of different events. The product also has to be able to be used in different environments, as for example in events like skiing contests, festivals, hockey games or weddings. In the assignment from the company 3TEMP, a powerful, flexible and user-friendly product was sought, that also had good ergonomic qualities. 

    The objective of the project has been to develop a product concept of a coffee machine for events, using the design methodology and an engineering approach. The concept shall meet the needs, requirements and expectations of the user and of the company. It should also have a design that because of its functionality and idiom stands out among today’s products.  

    The outcome of the project was a concept proposal of a coffee machine for events. The concept is based on knowledge of the user to make the product user-friendly by having good ergonomics and being easy to understand as well as use. The concept aligns with the vision of 3TEMP and is, thanks to its design and functionality, considered to stand out among today’s products.

  • 34.
    Anukam, Anthony
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013). University of Fort Hare, South Africa.
    Okoh, Omobola
    University of Fort Hare, South Africa.
    Mamphweli, Sampson
    Stellenbosch University, South Africa.
    Berghel, Jonas
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    A comparative analysis of the gasification performances of torrefied and untorrefied bagasse: Influence of feed size, gasifier design and operating variables on gasification efficiency2018In: International Journal of Engineering & Technology, E-ISSN 2227-524X, Vol. 7, no 2, p. 859-867Article in journal (Refereed)
    Abstract [en]

    This study conducted a comparative assessment of the gasification performances of torrefied and untorrefied bagasse with emphasis on feed size, gasifier design and operating conditions that would influence gasification efficiency. Torrefaction greatly improved the characteristics of bagasse and had significant impact on its gasification performance. The gasifier design parameters studied were throat angle and throat diameter. Temperature of input air and feed input were the gasifier operating conditions examined in the course of the gasification processes of both torrefied and untorrefied bagasse. These parameters were considered the most critical operating parameters that affect gasifier performance and, correlation between the parameters was established in the course of gasification. The results obtained showed higher gasification efficiency for torrefied bagasse in comparison to untorrefied bagasse under varied conditions of gasification, which was attributed mainly to changes in the characteristics of the torrefied material.  

  • 35.
    Arnberg, Johanna
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Physics (from 2013), Science, Mathematics and Engineering Education Research.
    Torrsubstansförluster vid lagring och hantering av träspån vid Härjeåns Energi AB2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Härjeåns Energi AB in Sveg is a company consisting a brand-new cogeneration plant and a biofuel plant where the company produces pellets out of wooden sawdust. Before pelleting, the sawdust is stored in a large stack. However, the company had noted that the amount of sawdust delivered to the stack minus the sawdust taken from the stack for pelleting did not add up to the sawdust left in the stack. At some point during storage and handling of the sawdust large quantities has disappeared. The purpose of this study was to investigate how and when the dry matter losses occur and the magnitude of the losses regarding two things: the dry matter losses associated with storing of the sawdust and the dry matter losses related to the handling of the sawdust. The most important goal of this study, for the company, was to create an equation that describes the amount of dry matter losses that reasonably should have disappeared from the stack depending on for how long the sawdust has been stored. Simply to be able to make a write-off of the sawdust inventory balances on a regular basis. The purpose and goals were answered by conducting a literature study on the subject, studying the company’s sawdust accounts and their way of handling the sawdust, and also by constructing two simulation models of the dry matter losses in the stack of sawdust.

    Dry matter losses resulting from the storage of biomass may occur through the decomposition mechanisms; respiration, biodegradation and thermal and chemical degradation. But the storage effect on fuel quality is complex. Time of storage, climatic conditions and the geometry and structure of the stacks are some factors that affect the change in biomass properties.

    This degradation, along with how the company manages the sawdust, contributes to dry matter losses. However, the largest contributing factor to the dry matter losses is the storage part. Some contributing factors are the size of the stack, if it’s been compacted and if the sawdust is stored open without coverage. When the models were built it turned out that the result was well in line with what actually had disappeared in the stack, according to the sawdust inventory, during the investigated years 2013-2017.

    For example, by reducing the maximum height of the stack to a maximum of 5-7 meters and apply the last-in-first-out-method on the spruce, while the pine can be stored for a longer time, would certainly contribute to reduced dry matter losses and, consequently, economic losses.

    In the future, however, more resources should be invested in research about storing the fraction of sawdust, as well as storing wood in stacks larger than a maximum height of 5-7 meters. Today there are no research at all within these two categories, but if there were, it could facilitate many energy-producing companies.

  • 36.
    Arnfeldt, Anna
    Karlstad University, Faculty of Economic Sciences, Communication and IT.
    Internationella inköp av byggmaterial: En studie av leverantörsval och inköpsuppföljning på NCC Construction Sverige AB2009Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

     

    Byggbranschen kritiseras för sina höga byggkostnader. Kostnaderna för byggmaterial utgör ca 45 procent av byggkostnaden i ett projekt vilket innebär att effektiva materialinköp och val av leverantörer är viktiga aktiviteter i ett byggföretag. De svenska materialpriserna är i många fall högre än i flera andra länder och en del företag har därför börjat göra inköp på den internationella marknaden för att kunna sänka sina inköpskostnader.

    NCC Construction Sverige AB är ett byggföretag som satsar hårt på att minska byggkostnaderna bl.a. genom effektiva inköp där en viktig del i satsningen handlar om internationella inköp. För att öka möjligheten att göra kostnadseffektiva val av leverantörer och förbättra inköpsarbetet vill företaget ha en bättre bild över vilka parametrar som är viktiga att beakta i samband med val av leverantörer och kunna identifiera vilka för- och nackdelar som en utländsk leverantör innebär samt vilka kostnader som vanligen uppstår vid internationella inköp. Dessutom finns ett behov av att få uppgifter om de internationella inköpens utfall på arbetsplatsen, främst en bild över totalkostnaden för inköpen och annan relevant information kopplad till dessa.

    Syftet med examensarbetet är därför att studera internationella inköp och undersöka företagets arbete inom detta område. Utifrån detta är syftet att ge rekommendationer på hur företaget kan arbeta med offertutvärdering, leverantörsval och uppföljning med fokus på de internationella inköpen.

    För att söka svar kring problemområdet har en studie av företagets inköparbete genomförts. En kvalitativ metod valdes för att samla in empirisk data, där ett antal personer från de yrkesgrupper som i första hand är involverade i internationella materialinköp, nämligen platschefer, inköpare och internationella inköpare, intervjuades. Genom att sammanlänka empiri och teori analyserades och besvarades frågeställningarna och rekommendationer kring problemområdet presenterades.

    Studien visar att det är ett antal parametrar som är viktiga att beakta inför valet av leverantörer och i samband med offertutvärdering vid internationella materialinköp för att kunna identifiera för- och nackdelarna med en leverantör. Både kvalitativa och kvantitativa såväl som kort- och långsiktiga effekter av ett visst val bör vägas in i värderingen. Relevanta parametrar är t.ex. projektets och projektorganisationens förutsättningar och resurser, inköpets totalkostnad, leveranssäkerhet, kvalitet och riskerna som vanligtvis är kopplade till internationella inköp. Kostnader som vanligtvis uppstår för projekten i samband med internationella materialinköp har identifierats och inkluderats i en kostnadsmall som kan användas av projekten vid offertutvärderingen för att uppskatta totalkostnaden för inköpet. Dessutom har parametrar kring inköpet som är viktiga att fånga upp och sprida inom organisationen identifierats och utifrån detta har en uppföljningsmall utformats. Denna kan vara ett stöd för att förbättra uppföljning och erfarenhetsåterföring bland projekten så att företaget därigenom kan effektivisera inköpsarbetet

  • 37. Asplén, Rickard
    Lekmöbel anpassad för förskolemiljö: Ett produktutvecklingsprojekt2018Independent thesis Basic level (degree of Bachelor), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    Abstract  The report deals with a product development project commissioned by Ludmilla Kompaniet at Almi Business Partner. The project is carried out in the course "Degree Project for degree of Bachelor of Science in innovation and design" at Karlstad University. The project supervisor is Monica Jacobsson, lecturer and the examining professor is Leo de Vin. The work is being examined in spring 2018. The commissioner Ludmilla Kompaniet had an idea of a furniture that children could use without harming themselves and they could play with it and use their full creativity. The furniture should not influence the child that will use it. The purpose of the project is to provide a concept for a furniture that is safe for children to use and that it should encourage the children to choose their own area of use. The project follows the design process described in Produktutveckling – effektiva metoder för konstruktion och design av Johannesson et al. (2004), which is taught at Karlstad University. The final concept is a furniture that is adapted for children in pre-school age. It can be used in different kind of ways and by children in different ages. The child controls how it wants the furniture to be used, in play or as traditional furniture. It is easy to wash and has a shape that prevents children from falling on it. The material is free of hormone-disturbing substances that can harm the health of the children. A function model has been manufactured and tested by children but not in the intended material as it exceeded the economy of the project.

  • 38.
    Axelsson, Johan
    Karlstad University, Faculty of Health, Science and Technology (starting 2013).
    Konstruktion av XC500 skruvtransportör2017Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [sv]

    Examensarbetet har utförts på uppdrag av Autofric AB i samarbete med Nordic Water som avslutning på högskoleingenjörsprogrammet inom Maskinteknik på Karlstad Universitet under våren 2017.

    Arbetet behandlar konstruktion av en skruvtransportör som är avsedd att användas i vattenreningsverk. Nordic Water konstruerar och säljer idag skruvtransportörer under serienamnet XC. För att kunna utöka sitt utbud för kunder vill de nu konstruera en skruvtransportör i diameterstorlek 500 mm, XC500.

    Under konstruktionsarbetet har kraftanalyser utförts för att förstå vilka krafter som angriper drivenheten på skruvtransportören. Vidare har hållfasthetsberäkningar utförts på de kritiska delar hos drivenheten för att kunna dimensionera dessa delar korrekt. Finita elementmetoden har tillämpats på de delar hos drivenheten med komplicerade geometrier och randvillkor. 

    Vid konstruktion av komponenter som finns i olika varianter har familjetabeller använts vid modellering. På så sätt kan Nordic Water snabbt ta fram 3D-modeller i olika dimensioner vid framtida konstruktionsarbete. Ett pneumatisktteleskoputkast har analyserats och modellerats. En viktanalys utfördes tillsammans med statikberäkningar för att kunna bestämma om tänkta lyftkolvar skulle klara dimensionsökningen XC500 transportören medför.

    Målet att konstruera enklare komponenter samt analysera drivenheten har uppfyllts med gott resultat. Ritningsunderlag har tagits fram för över 50 komponenter och drivenheten har dimensionerats för att klara beräknad belastning. Målet att konstruera benkonstruktionen hann inte uppfyllas på grund av bristande tidsrymd.

  • 39.
    Bach, Dennis
    Karlstad University, Faculty of Health, Science and Technology (starting 2013).
    Konceptframtagning för vinkelväxel: En studie på tätningsmekanism och utformning för att undvika oljeläckage2018Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    This project is part of the examination in the education bachelor’s degree in innovation technology and design. The assignment is provided by GKN Driveline Köping AB. GKN Driveline is global leading with their AWD system and is in a constant development. Challenges which they are aware of, to minimize environmental impact by constantly reducing weight and power loss on their power take of units. And at the same time to consider lowering the development cost and short lead times. Which has led to detection during tests with problems such as oil leakage between the split plane of the housing and cover. GKN wish to consider a solution to prevent this event to happen during an early design phase, thus provide higher quality, customer satisfaction and less impact on the environment. The purpose of this project is to identify the factors that affect oil leakage at the split plane between housing and cover in power transfer units and find a solution to prevent this. The goal is to use the design process to contribute to a concept that will give rise to a basis of new development of power transfer units. The milestone in the project is to illustrate and describe the chosen concept with its pros and cons as well as aspects that affect oil leakage. Methods covered in the project include project planning, pilot study, product specification, generating-, evaluating and developing the concept. This resulted in a concept that illustrates its advantage with the freedom to design the split plane. This delivered concept is a basis for continued development and optimization to be a fully functional product in the future.

  • 40.
    Bagheri, R.
    et al.
    University of Zanjan, Iran.
    Ayatollahi, M.
    University of Zanjan, Iran.
    Mousavi, Mahmoud
    Aalto University, Finland.
    Analysis of cracked piezoelectric layer with imperfect non-homogeneous orthotropic coating2015In: International Journal of Mechanical Sciences, ISSN 0020-7403, E-ISSN 1879-2162, Vol. 93, p. 93-101Article in journal (Refereed)
    Abstract [en]

    Abstract The fracture problem for a medium composed of a cracked piezoelectric strip with functionally graded orthotropic coating is studied. The layer is subjected to anti-plane mechanical and in-plane electrical loading. In this paper, we first address, the problem of a screw dislocation located in a substrate which is imperfectly bonded to the coating. Then, in order to model the cracked piezoelectric layer, by means of the dislocation solution, we construct integral equations for the layer, in which the unknown variables are dislocation densities. These unknowns are determined through satisfaction of the boundary conditions on the crack faces. By use of the dislocation densities, the field intensity factors are determined. Several examples are presented to demonstrate the applicability of the proposed solution. ", keywords = Piezoelectric strip; Functionally graded layer; Imperfect bonding; Multiple cracks; Stress intensity factors, isbn = 0020-7403, doi=https://doi.org/10.1016/j.ijmecsci.2014.11.025

  • 41.
    Bagheri, R.
    et al.
    University of Zanjan, Iran.
    Ayatollahi, M.
    University of Zanjan, Iran.
    Mousavi, Mahmoud
    Aalto University, Finland.
    Analytical solution of multiple moving cracks in functionally graded piezoelectric strip2015In: Applied mathematics and mechanics, ISSN 0253-4827, E-ISSN 1573-2754, Vol. 36, no 6, p. 777-792Article in journal (Refereed)
    Abstract [en]

    The dynamic behaviors of several moving cracks in a functionally graded piezoelectric (FGP) strip subjected to anti-plane mechanical loading and in-plane electrical loading are investigated. For the first time, the distributed dislocation technique is used to construct the integral equations for FGP materials, in which the unknown variables are the dislocation densities. With the dislocation densities, the field intensity factors are determined. Moreover, the effects of the speed of the crack propagation on the field intensity factors are studied. Several examples are solved, and the numerical results for the stress intensity factor and the electric displacement intensity factor are presented graphically finally.

  • 42.
    Balk, Leonard
    Karlstad University, Faculty of Health, Science and Technology (starting 2013).
    Foldable load carrier: Product development and prototyping2019Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Keywords: Material management, load carrier, product development process, CAD, CAE, CAM

    In this master thesis a foldable load carrier was developed as part of improved material management at AQ Components in Västerås. One of their product lines involves service hatches for trains that are transported within the facility throughout the manufacturing process. Currently, a custom-built load carrier is used to transport the hatches between assembling and painting stations. Unfortunately, the carrier has design and systematic flaws that needs to be resolved. The current carrier is not very protective and occupies a lot of space. The hatches also return from the painting station in an unpredictable order. Before investing in solutions, the subject of material management was studied further. This is a branch within logistics that focus on the internal material flow within industries. Companies that wish to stay competitive continuously invest in improved material management to achieve more profitable material flow, increased capacity, increased regularity and availability, better ergonomics and goods protection. The thesis work followed a classic product development process with focus on a synthesis-analysis loop. After establishing a project plan, the current solution was investigated where the customer need was identified in a product specification. Five concepts were generated and screened, where the most objectively advantageous concept was developed. The new carrier was designed using CAD, in parallel to structural analysis using both CAE and theoretical calculations. The manufacturing process utilizes the sheet metal specialization of AQ Components, where the components were tactically nested using CAM for material efficient laser cutting. Prototyping was carried out before hand over, to ensure the carrier works as well in practise as in theory. The developed load carrier is designed with an outer protective frame, with scratch resistant arms for inserting the service hatches. The frame is foldable with two lockable positions for in and out of use. Once folded, the width is reduced to 1/3rd of the original width. With further safety analysis the carrier can then also be hanged away (with forklift) so that it practically occupies no space at all. The carrier can be transported by forklift in pairs or more, with a total capacity of at least 20 service hatches. The carrier is equipped with an intuitive tracking system, where the carriers and slots are marked. This allows the hatches to return in the order they were sent. The carrier and solution deliver not only on the product specification, but also on the key objectives of improved material management.

  • 43.
    Baradi, Divyank
    Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Control strategies and inspection methods for welded part2013Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Present and future demonstrator designs were used to demonstrate the quality assurance of welds. The NDT methods tested on prototype demonstrator parts are: visual inspection, radius gauges, throat size gauge, liquid-penetrant testing, magnetic particle testing and ultrasonics with pulse echo and phased array. The other methods like eddy current, time of flight diffraction, radiography, impression test, macro test and infrared thermographs are currently being analyzed along with their inspection costs.

     

    The control plans for present and future designs with corresponding present and future NDT methods are suggested to minimize a shift in process.

    • Magnetic particle testing revealed a lack of fusion and cracks for fillet welds, whereas ultrasonic pulse echo and phased array identified an internal lack of fusion, inner pores/slag inclusions on butt welds.
    • Ultrasonic PAUT & TOFD could be used for accurate defect identification and thermography for online identification of lack of penetration, depth of penetration and weld parameters.
  • 44.
    Barbier, Christophe
    et al.
    Karlstad University, Faculty of Technology and Science, Materials Science. Karlstad University, Faculty of Health, Science and Technology (starting 2013), Paper Surface Centre. Karlstad University, Faculty of Technology and Science, Department of Chemical Engineering. Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Beghello, L
    Magnetic printing for packaging industry: methods and feasibility2006Conference paper (Refereed)
  • 45.
    Barbier, Christophe
    et al.
    Karlstad University, Faculty of Technology and Science, Materials Science. Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences, Paper Surface Centre. Karlstad University, Faculty of Technology and Science, Department of Chemical Engineering. Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Larsson, Per-Lennart
    Östlund, Sören
    Hallbäck, Nils
    Karlstad University, Faculty of Technology and Science, Materials Science. Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Karathanasis, Michael
    On material characterization of paper coating materials by microindentation testing2005In: JCT: Journal of Coatings Technology, ISSN 0361-8773, Vol. 2, no 6, p. 463-471Article in journal (Refereed)
    Abstract [en]

    Microindentation as a method for determining important material properties of paper coating materials is studied experimentally and numerically. The bulk of the investigation is concentrated upon the short-lived elastic part of a spherical indentation test, but determination of the failure stress of the coating is also discussed. The results indicate that microindentation can be a powerful tool for material characterization of these materials, but only if careful efforts are made to account for the influence from plasticity as well as from boundary effects

  • 46.
    Barbier, Christophe
    et al.
    Karlstad University, Faculty of Technology and Science, Materials Science. Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences, Paper Surface Centre. Karlstad University, Faculty of Technology and Science, Department of Chemical Engineering. Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Larsson, PL
    KTH Stockholm.
    Östlund, S
    Experimental investigation of damage at folding of coated papers2002In: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 17, no 1, p. 34-Article in journal (Refereed)
    Abstract [en]

    To achieve a better understanding of the folding properties of coated papers pertinent to the mechanical behaviour, a microscopic investigation was performed. The influence on the damage levels in the coating from such features as delamination, humidity and paper thickness have been studied

  • 47.
    Barbier, Christophe
    et al.
    Karlstad University, Faculty of Technology and Science, Materials Science. Karlstad University, Faculty of Health, Science and Technology (starting 2013), Paper Surface Centre. Karlstad University, Faculty of Technology and Science, Department of Chemical Engineering. Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Larsson, PL
    Östlund, S
    Numerical investigation of folding of coated papers2005In: Composite StructuresArticle in journal (Refereed)
    Abstract [en]

    Folding of coated paper is examined numerically using the finite element method. Particular emphasis is put on the behaviour of field variables relevant for cracking of the coating layers. In the numerical analysis, the basepaper is modelled as an anisotropic elasticplastic material (both elastic and plastic anisotropy is accounted for) while the constitutive behaviour of the coating layers are approximated by classical (Mises) elastoplasticity. The numerical results suggest, among other things, that particular forms of plastic anisotropy can substantially reduce the maximum strain levels in the coating. It is also shown that delamination buckling, in the present circumstances, will have a very small influence on the strain levels in the coating layer subjected to high tensile loading

  • 48.
    Barbier, Christophe
    et al.
    Karlstad University, Faculty of Technology and Science, Materials Science. Karlstad University, Faculty of Health, Science and Technology (starting 2013), Paper Surface Centre. Karlstad University, Faculty of Technology and Science, Department of Chemical Engineering. Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Larsson, PL
    Östlund, S
    On dynamic effects at folding of coated papers2005In: Composite StructuresArticle in journal (Refereed)
  • 49.
    Barbier, Christophe
    et al.
    Karlstad University, Faculty of Technology and Science, Materials Science. Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences, Paper Surface Centre. Karlstad University, Faculty of Technology and Science, Department of Chemical Engineering. Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Larsson, PL
    KTH Stockholm.
    Östlund, S
    On the effect of high anisotropy at folding of coated papers2007In: Composite structures, ISSN 0263-8223, E-ISSN 1879-1085, Vol. 72, no 3, p. 330-338Article in journal (Refereed)
    Abstract [en]

    A finite element procedure, developed in order to account for the effect of high anisotropy at folding of coated papers, is presented. The anisotropic behaviour (with very low stiffness in the thickness direction) is modelled using stiff structural elements (trusses and beams). The numerical results indicate that high elastic anisotropy leads to lower strain levels at folding than reported in previous analyses where this effect was not accounted for. High plastic anisotropy, on the other hand, will contradict this result

  • 50.
    Barbier, Christophe
    et al.
    Karlstad University, Faculty of Technology and Science, Materials Science. Karlstad University, Faculty of Health, Science and Technology (starting 2013), Paper Surface Centre. Karlstad University, Faculty of Technology and Science, Department of Chemical Engineering. Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Larsson, PL
    Östlund, S
    Eklund, J
    Folding of printed papers: experiments and numerical analysis2003Conference paper (Other (popular science, discussion, etc.))
    Abstract [en]

    Folding of digital prints has been investigated experimentally in order to determine the influence from different features on the residual strength of the folded paper. In particular, the effect of toner-layer, paper-fibre orientation and pre-creasing is investigated and the experimental results are supplemented with numerical ones based on the finite element method. The results indicate that creasing, and to a less extend also fibre orientation, is the most important factor influencing the residual tensile strength after folding

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